This invention relates to the art of furnaces for liquifying non-combustible materials, and more particularly to a new and improved method and apparatus for removing molten material from such furnaces.
One area of the use of the present invention is in slagging pyrolysis solid waste disposal systems although the principles of the invention can be variously applied. In these and other systems to which the present invention is applicable, non-combustible material such as solid wastes or materials including metal, glass and mixtures of organic and inorganic material is charged into a furnace or combustion chamber wherein it is reduced to a slag which then is removed therefrom. One approach of the prior art to the problem of slag removal, known as tapping, was to plug a drain hole in the bottom of the furnace or combusion chamber with a refractory plug and remove the plug periodically to drain the molten material. Another approach was to continuously drain the furnace using a refractory lined trough, also known as a runner, to direct the material to some collection point. In this approach, if the trough is not thoroughly heated, some of the molten material is allowed to cool thereby increasing the viscosity and sometimes solidifying, causing build-ups in the horizontal runs and staliactite formations at vertical dropping points. On a continuously draining furnace, the formations can cause serious interruption to normal operations.